Generally speaking, a warehouse can lose significant amounts of money because of errors in storing items on pallets. This causes problems with replenishment workflows. The main problems for losses in these workflows are pallets lost due to storage at incorrect slot locations and “twilight zone” problems, that is pallets being stored randomly and not in designated storage slots. In either case, the locations of items on pallets in the warehouse are unknown.
In one aspect of the problem, pallets may be placed in an incorrect slot location due to misidentification. Identifying tags on the pallets, which may be labels, barcodes, alphanumeric codes or the like, are usually close to ground level on the pallet. The forklift operator may misread the identifying tag because of its location and therefore mistakenly put a pallet into slot A when the tag indicates the pallet belongs in slot B. At a later time a forklift operator may have a new pallet designated for slot B. Because slot B is already occupied, the forklift operator drops the pallet in the twilight zone to save time, instead of relocating the pallets to their proper slots. This creates an additional problem, now two pallets are lost.
In another scenario, there are two adjacent slots. Slot A is occupied with the pallet designated for slot B. The forklift operator sees one empty slot (slot B) in close proximity to where his new pallet is designated (slot A) and mistakenly puts the new pallet in the wrong slot. Even though the two pallets are close to their designated storage slots, both become lost in the system.
In a further scenario, the forklift operator may incorrectly record which slot he has put a pallet.
In another scenario, forklift operators working on productivity incentives may put away pallets far from the picking location in order to improve their productivity, ultimately resulting in long travel times when retrieving the pallets.
When pallets are deposited in the “twilight zone,” pallets are lost due to disorganization. Pallets in this zone may go past expiration dates or be lost to shipping deadlines. These pallets may have to be written off as a loss to the owner as their whereabouts are unknown. Even if a pallet is not lost, but is located in the “twilight zone,” productivity suffers as the pallet retrieval is more complicated and may pose longer travel to shelf.
Many warehouses have computer assisted warehouse management systems (WMS). A WMS may require a forklift operator to scan the pallet identifying tag with a handheld barcode reader and record pallet location with the reader. This information is sent to a WMS terminal. However, human error in entering data or placing the pallet gives the WMS incorrect information, resulting in lost pallets.
Some WMS computer terminals are mounted on the forklift itself. A driver may have to slow down when reading data on the terminal or be distracted in driving the forklift, possibly causing an accident. Both scenarios limit productivity.
Therefore, a need exists for a warehouse management system for tracking pallet storage which overcomes the problems discussed hereinbefore.